Solid state memory storage devices may be used to store data. Such solid state storage devices may be based on solid state memory such as, for example, Phase Change Memory (PCM), Spin Torque Magnetic Random Access Memory, that degrades as data are written to the memory. Only a limited number of writes to solid state memory may thus be permissible before the solid state memory loses its ability to reliably retain data. As such, even with perfect wear leveling, it may become necessary for a solid state memory storage device to migrate data from one region of storage to another fresh region of storage, while a user workload is in progress.